does anybody know how to get the "We’re in for some Chop" acheivment on halo 3

[mr. roberts]

does anybody know how to get the "We’re in for some Chop" acheivment on halo 3

campaighn? ive tried using trip mines and the power drain without much success if anybodys done it on the capaighn howd u manage

 

[mkburman]

this is how i got mine, go to the tsavo highway level, from there keep playing until you reach the spot where there is a giant purple shield blocking a tunnel. if youre near that area you should find a couple of bunkers. one of the bunkers have trip mines in them. take a trip mine and wait until a chopper comes and trys to run you over. throw the trip mine where the chopper is going and boom! achievement unlocked